The Unicity Distance for the DES cipher is around $8.6$ characters, and can be calculated using the $U=H(k)/D$ formula, where $D = R - r$, and where $R = 8$ is the number of bits in a byte (ASCII is 7 ...

I've been looking into the difference between PRNGs and proper RNG techniques. One that I particularly like is the idea of tuning a radio to a certain frequency and bandwidth and just listening to the ...

Why is there a need to generate more than one high entropy seed? It would seem like if the original source of entropy is high quality, than some 512 bits should be more than enough to seed a CSPRNG ...

Here is a cartoon about password entropy. http://xkcd.com/936/
I dont quite understand how the entropy is calculated in the cartoon assuming they are calculate correctly. But in general, I dont have ...

The Von Neumann randomness extractor is explicitly mentioned in the randomness extractor page of Wikipedia, but strangely enough that page does not contain any reference to whitening the results of an ...

I'm implementing an entropy gathering program.
For that I collect 2 bits from two gpio-pins connected to a random source.
I whiten this stream of bits using the von Neumann decorrelation algorithm. ...

Assume that I have two sources of entropy (say, a hardware RNG and a CSPRNG) and that the two sources are independent (do not know anything about the internal state of the other RNG). Can I mix them ...

How would one go about generating Encryption Keys from Biometric Fingerprint Templates extracted from a fingerprint using either Griaule SDK or DigitalPersona SDK or any other SDK that will return the ...

There are many cases in maths where doing the same thing over and over again will bring you closer to a value. Derivation of polynomials is the striking example: no matter what you start with, you end ...

I want to create a brain wallet using a custom diceware since I don't like the original one. Instead of 7776 words it has 46656 because I use 6 dice for each word instead of 5, and also it only has ...

My app on Android uses the built-in motion sensors to collect seed-data for the PRNG (java.security.SecureRandom) that is later to be used for key-generation.
The user is told to shake the device so ...

I need to write some high-level security requirements which include a random number generator suitable for use in cryptography. I don't need something very formal, this isn't a security certification ...

Does mapping a large character-set hash onto a small character-set hash lower entropy for a fixed size substring?
I'm writing a python app that involves generating passwords for websites. During the ...

I have a potentially infinite stream of data originating in some physical phenomena that may expose random behavior (due to quantum effects, thermal noise, the butterfly effect in chaotic dynamical ...

I want to store data encrypted within an Android application. Keeping an encryption key safe outside the app is not an option so I looked into password derived key algorithms.
I found a nice example ...

I would like to prompt users for a single passphrase to establish trust with separate, normally (but not always) complementary systems from one password input.
I'm essentially looking for a box where ...

I know how to calculate the entropy of a key that relates to its selection process. For example if the key space is $1000$, entropy of a randomly chosen key is $1000$. Suppose now you have two keys ...